#region Copyright & License

//
// Copyright 2001-2005 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

#endregion

using System;
using System.IO;
using log4net.Core;

namespace log4net.Util {
  /// <summary>
  /// Subclass of <see cref="QuietTextWriter"/> that maintains a count of 
  /// the number of bytes written.
  /// </summary>
  /// <remarks>
  /// <para>
  /// This writer counts the number of bytes written.
  /// </para>
  /// </remarks>
  /// <author>Nicko Cadell</author>
  /// <author>Gert Driesen</author>
  public class CountingQuietTextWriter : QuietTextWriter {
    #region Public Instance Constructors

    /// <summary>
    /// Constructor
    /// </summary>
    /// <param name="writer">The <see cref="TextWriter" /> to actually write to.</param>
    /// <param name="errorHandler">The <see cref="IErrorHandler" /> to report errors to.</param>
    /// <remarks>
    /// <para>
    /// Creates a new instance of the <see cref="CountingQuietTextWriter" /> class 
    /// with the specified <see cref="TextWriter" /> and <see cref="IErrorHandler" />.
    /// </para>
    /// </remarks>
    public CountingQuietTextWriter(TextWriter writer, IErrorHandler errorHandler) : base(writer, errorHandler) {
      m_countBytes = 0;
    }

    #endregion Public Instance Constructors

    #region Override implementation of QuietTextWriter

    /// <summary>
    /// Writes a character to the underlying writer and counts the number of bytes written.
    /// </summary>
    /// <param name="value">the char to write</param>
    /// <remarks>
    /// <para>
    /// Overrides implementation of <see cref="QuietTextWriter"/>. Counts
    /// the number of bytes written.
    /// </para>
    /// </remarks>
    public override void Write(char value) {
      try {
        base.Write(value);

        // get the number of bytes needed to represent the 
        // char using the supplied encoding.
        m_countBytes += Encoding.GetByteCount(new[] {value});
      } catch (Exception e) {
        ErrorHandler.Error("Failed to write [" + value + "].", e, ErrorCode.WriteFailure);
      }
    }

    /// <summary>
    /// Writes a buffer to the underlying writer and counts the number of bytes written.
    /// </summary>
    /// <param name="buffer">the buffer to write</param>
    /// <param name="index">the start index to write from</param>
    /// <param name="count">the number of characters to write</param>
    /// <remarks>
    /// <para>
    /// Overrides implementation of <see cref="QuietTextWriter"/>. Counts
    /// the number of bytes written.
    /// </para>
    /// </remarks>
    public override void Write(char[] buffer, int index, int count) {
      if (count > 0)
        try {
          base.Write(buffer, index, count);

          // get the number of bytes needed to represent the 
          // char array using the supplied encoding.
          m_countBytes += Encoding.GetByteCount(buffer, index, count);
        } catch (Exception e) {
          ErrorHandler.Error("Failed to write buffer.", e, ErrorCode.WriteFailure);
        }
    }

    /// <summary>
    /// Writes a string to the output and counts the number of bytes written.
    /// </summary>
    /// <param name="str">The string data to write to the output.</param>
    /// <remarks>
    /// <para>
    /// Overrides implementation of <see cref="QuietTextWriter"/>. Counts
    /// the number of bytes written.
    /// </para>
    /// </remarks>
    public override void Write(string str) {
      if (str != null && str.Length > 0)
        try {
          base.Write(str);

          // get the number of bytes needed to represent the 
          // string using the supplied encoding.
          m_countBytes += Encoding.GetByteCount(str);
        } catch (Exception e) {
          ErrorHandler.Error("Failed to write [" + str + "].", e, ErrorCode.WriteFailure);
        }
    }

    #endregion Override implementation of QuietTextWriter

    #region Public Instance Properties

    /// <summary>
    /// Gets or sets the total number of bytes written.
    /// </summary>
    /// <value>
    /// The total number of bytes written.
    /// </value>
    /// <remarks>
    /// <para>
    /// Gets or sets the total number of bytes written.
    /// </para>
    /// </remarks>
    public long Count {
      get { return m_countBytes; }
      set { m_countBytes = value; }
    }

    #endregion Public Instance Properties

    #region Private Instance Fields

    /// <summary>
    /// Total number of bytes written.
    /// </summary>
    long m_countBytes;

    #endregion Private Instance Fields
  }
}